What does Brissaud's infantilism mean?

Brissaud's infantilism meaning in Medical Dictionary

An eponym this is certainly little-used (in the united states) for hypothyroidism (subnormal activity of this thyroid gland) that starts after beginning and it is manifest by features including delays in development and development and myxedema surfacing during infancy. Myxedema is a dry waxy type of swelling, usually with distended lips and nose. Infantile hypothyroidism is similar to infantile myxedema. Called for French physician Edouard Brissaud (1852-1909).